<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title></title>
</head>
<body>
<script type="text/javascript">
	//二维数组
	let arr = [[1, 2, 3],["h","i"]]
	arr[0][0] //外层 内层
	for(let i = 0; i<arr.length; i++){
		for(let j = 0 ;j<arr[i].length; j++){
			console.log(arr[i][j])
		}
	}
</script>
</body>
</html>